diff --git a/src/lib/cart.ts b/src/lib/cart.ts
index e0308df..537a129 100644
--- a/src/lib/cart.ts
+++ b/src/lib/cart.ts
@@ -1,5 +1,6 @@
 import type { CartItem, CartItemInput } from "@/models/cart.model";
-import { type Product } from "@/models/product.model";
+// import { type Product } from "@/models/product.model";
+import { type VariantAttributeValue } from "@/models/variant-attribute.model";
 import {
   alterQuantityCartItem,
   deleteRemoteCartItem,
@@ -18,14 +19,14 @@ export async function getCart(userId?: number, sessionCartId?: string) {
 export async function addToCart(
   userId: number | undefined,
   sessionCartId: string | undefined,
-  productId: Product["id"],
+  attributeValueId: VariantAttributeValue["id"],
   quantity: number = 1
 ) {
   try {
     const updatedCart = await alterQuantityCartItem(
       userId,
       sessionCartId,
-      productId,
+      attributeValueId,
       quantity
     );
     return updatedCart;
@@ -62,10 +63,10 @@ export function calculateTotal(items: CartItem[] | CartItemInput[]): number {
     // Type guard to determine which type we're working with
     if ("product" in item) {
       // CartItem - has a product property
-      return total + item.product.price * item.quantity;
+      return total + Number(item.product.price) * item.quantity;
     } else {
       // CartItemInput - has price directly
-      return total + item.price * item.quantity;
+      return total + Number(item.price) * item.quantity;
     }
   }, 0);
 }
diff --git a/src/models/cart.model.ts b/src/models/cart.model.ts
index 8550190..53333ce 100644
--- a/src/models/cart.model.ts
+++ b/src/models/cart.model.ts
@@ -33,7 +33,7 @@ export type CartProductInfo = Pick<
 export type CartItemWithProduct = {
   product: CartProductInfo;
   quantity: number;
-  attributeId: number;
+  attributeValueId: number;
 };
 
 // Tipo para el carrito con items y productos incluidos
diff --git a/src/models/product.model.ts b/src/models/product.model.ts
index 489125f..47259f5 100644
--- a/src/models/product.model.ts
+++ b/src/models/product.model.ts
@@ -5,6 +5,7 @@ export type Product = PrismaProduct & {
   price?: number | null;
   minPrice?: number | null;
   maxPrice?: number | null;
+  variantAttributeValues?: VariantAttributeValue[];
 };
 
 export type ProductVariantValue = PrismaProduct & {
diff --git a/src/routes/cart/add-item/index.tsx b/src/routes/cart/add-item/index.tsx
index ac49758..06745d1 100644
--- a/src/routes/cart/add-item/index.tsx
+++ b/src/routes/cart/add-item/index.tsx
@@ -7,14 +7,14 @@ import type { Route } from "../+types";
 
 export async function action({ request }: Route.ActionArgs) {
   const formData = await request.formData();
-  const productId = Number(formData.get("productId"));
+  const attributeValueId = Number(formData.get("attributeValueId"));
   const quantity = Number(formData.get("quantity")) || 1;
   const redirectTo = formData.get("redirectTo") as string | null;
   const session = await getSession(request.headers.get("Cookie"));
   const sessionCartId = session.get("sessionCartId");
   const userId = session.get("userId");
 
-  await addToCart(userId, sessionCartId, productId, quantity);
+  await addToCart(userId, sessionCartId, attributeValueId, quantity);
 
   return redirect(redirectTo || "/cart");
 }
diff --git a/src/routes/cart/index.tsx b/src/routes/cart/index.tsx
index d330cef..e80a88b 100644
--- a/src/routes/cart/index.tsx
+++ b/src/routes/cart/index.tsx
@@ -30,7 +30,7 @@ export default function Cart({ loaderData }: Route.ComponentProps) {
           Carrito de compras
         </h1>
         <div className="border-solid border rounded-xl flex flex-col">
-          {cart?.items?.map(({ product, quantity, id }) => (
+          {cart?.items?.map(({ product, quantity, id, attributeValueId }) => (
             <div key={product.id} className="flex gap-7 p-6 border-b">
               <div className="w-20 rounded-xl bg-muted">
                 <img
@@ -55,14 +55,14 @@ export default function Cart({ loaderData }: Route.ComponentProps) {
                 </div>
                 <div className="flex flex-col gap-2 md:flex-row md:justify-between md:items-center">
                   <p className="text-sm font-medium">
-                    ${product.price.toFixed(2)}
+                    ${product.price!.toFixed(2)}
                   </p>
                   <div className="flex gap-4 items-center">
                     <Form method="post" action="/cart/add-item">
                       <input type="hidden" name="quantity" value="-1" />
                       <Button
-                        name="productId"
-                        value={product.id}
+                        name="attributeValueId"
+                        value={attributeValueId}
                         variant="outline"
                         size="sm-icon"
                         disabled={quantity === 1}
@@ -77,8 +77,8 @@ export default function Cart({ loaderData }: Route.ComponentProps) {
                       <Button
                         variant="outline"
                         size="sm-icon"
-                        name="productId"
-                        value={product.id}
+                        name="attributeValueId"
+                        value={attributeValueId}
                       >
                         <Plus />
                       </Button>
diff --git a/src/routes/checkout/index.tsx b/src/routes/checkout/index.tsx
index 5bfbbde..8b23f33 100644
--- a/src/routes/checkout/index.tsx
+++ b/src/routes/checkout/index.tsx
@@ -266,7 +266,7 @@ export default function Checkout({
                     <div className="flex text-sm font-medium gap-4 items-center self-end">
                       <p>{quantity}</p>
                       <X className="w-4 h-4" />
-                      <p>S/{product.price.toFixed(2)}</p>
+                      <p>S/{product.price!.toFixed(2)}</p>
                     </div>
                   </div>
                 </div>
diff --git a/src/routes/product/index.tsx b/src/routes/product/index.tsx
index da547f3..545544c 100644
--- a/src/routes/product/index.tsx
+++ b/src/routes/product/index.tsx
@@ -1,9 +1,12 @@
-import { Form, useNavigation } from "react-router";
 import { useState } from "react";
+import { Form, useNavigation } from "react-router";
+
 import { Button, Container, Separator } from "@/components/ui";
 import { type Product } from "@/models/product.model";
 import { getProductById } from "@/services/product.service";
+
 import NotFound from "../not-found";
+
 import type { Route } from "./+types";
 
 export async function loader({ params }: Route.LoaderArgs) {
@@ -26,7 +29,18 @@ export default function Product({ loaderData }: Route.ComponentProps) {
   }
 
   const showSizeSelector = product.categoryId === 1 || product.categoryId === 3;
-  
+
+  const getAttributeValueId = () => { // AQUI TRAER EL AttributeValueId con el cambio de SEBAS
+    if (
+      !product.variantAttributeValues ||
+      product.variantAttributeValues.length === 0
+    ) {
+      return undefined;
+    }
+    // Devuelve el attributeId de la posición 0
+    return product.variantAttributeValues[0].id;
+  };
+
   const getSizeOptions = () => {
     if (product.categoryId === 3) {
       return {
@@ -34,8 +48,8 @@ export default function Product({ loaderData }: Route.ComponentProps) {
         options: [
           { value: "Small", label: "3x3 cm" },
           { value: "Medium", label: "5x5 cm" },
-          { value: "Large", label: "10x10 cm" }
-        ]
+          { value: "Large", label: "10x10 cm" },
+        ],
       };
     } else {
       return {
@@ -43,8 +57,8 @@ export default function Product({ loaderData }: Route.ComponentProps) {
         options: [
           { value: "Small", label: "Small" },
           { value: "Medium", label: "Medium" },
-          { value: "Large", label: "Large" }
-        ]
+          { value: "Large", label: "Large" },
+        ],
       };
     }
   };
@@ -67,7 +81,14 @@ export default function Product({ loaderData }: Route.ComponentProps) {
               {product.title}
               {showSizeSelector && (
                 <span className="text-muted-foreground">
-                  {" "}({sizeOptions.options.find(option => option.value === selectedSize)?.label})
+                  {" "}
+                  (
+                  {
+                    sizeOptions.options.find(
+                      (option) => option.value === selectedSize
+                    )?.label
+                  }
+                  )
                 </span>
               )}
             </h1>
@@ -78,12 +99,16 @@ export default function Product({ loaderData }: Route.ComponentProps) {
 
             {showSizeSelector && (
               <div className="mb-9">
-                <p className="text-sm font-semibold text-accent-foreground mb-2">{sizeOptions.label}</p>
+                <p className="text-sm font-semibold text-accent-foreground mb-2">
+                  {sizeOptions.label}
+                </p>
                 <div className="flex gap-2">
                   {sizeOptions.options.map((option) => (
                     <Button
                       key={option.value}
-                      variant={selectedSize === option.value ? "default" : "secondary"}
+                      variant={
+                        selectedSize === option.value ? "default" : "secondary"
+                      }
                       size="lg"
                       onClick={() => setSelectedSize(option.value)}
                     >
@@ -100,20 +125,25 @@ export default function Product({ loaderData }: Route.ComponentProps) {
                 name="redirectTo"
                 value={`/products/${product.id}`}
               />
+              <input
+                type="hidden"
+                name="attributeValueId"
+                value={getAttributeValueId() ?? ""}
+              />
               <Button
                 size="xl"
                 className="w-full md:w-80"
                 type="submit"
-                name="productId"
-                value={product.id}
+                // name="productId"
+                // value={product.id}
                 disabled={cartLoading}
               >
                 {cartLoading ? "Agregando..." : "Agregar al Carrito"}
               </Button>
             </Form>
-            
+
             <Separator className="my-6" />
-            
+
             <div>
               <h2 className="text-sm font-semibold text-accent-foreground mb-6">
                 Características
@@ -129,4 +159,4 @@ export default function Product({ loaderData }: Route.ComponentProps) {
       </section>
     </>
   );
-}
\ No newline at end of file
+}
diff --git a/src/services/cart.service.ts b/src/services/cart.service.ts
index af05fa3..417bcbb 100644
--- a/src/services/cart.service.ts
+++ b/src/services/cart.service.ts
@@ -138,7 +138,7 @@ export async function createRemoteItems(
     await prisma.cartItem.createMany({
       data: items.map((item) => ({
         cartId: cart.id,
-        attributeValueId: item.attributeId, // modificar
+        attributeValueId: item.attributeValueId,
         quantity: item.quantity,
       })),
     });
@@ -154,13 +154,13 @@ export async function createRemoteItems(
 export async function alterQuantityCartItem(
   userId: User["id"] | undefined,
   sessionCartId: string | undefined,
-  attributeId: number,
+  attributeValueId: number,
   quantity: number = 1
 ): Promise<CartWithItems> {
   const cart = await getOrCreateCart(userId, sessionCartId);
 
   const existingItem = cart.items.find(
-    (item) => item.attributeValueId === attributeId
+    (item) => item.attributeValueId === attributeValueId
   );
 
   if (existingItem) {
@@ -180,7 +180,7 @@ export async function alterQuantityCartItem(
     await prisma.cartItem.create({
       data: {
         cartId: cart.id,
-        attributeValueId: attributeId,
+        attributeValueId: attributeValueId,
         quantity,
       },
     });